The world is always full of impermanence, chance and unpredictability.
No one knows what will happen to them tomorrow.
Song Kun is an old man in the criminal police brigade of the High-tech Zone and has led many criminal police officers.
I also know most of the people in the criminal investigation detachment.
Even if the criminal police officers at the scene of the crime have never met Song Kun in person, most of them have heard of his name.
Maybe yesterday, or even early this morning, there were still people who were envious of Song Kun Mashan's retirement life.
However, what I saw today was only a cold corpse.
For many people in the Criminal Police Brigade of the High-tech Zone, this is a scene that is difficult to accept.
Although Qin Yong has arrived at the scene in person, the main commander is Yuan Shaokang, captain of the High-tech Zone Criminal Police Brigade.
After all, Song Kun was his, and this was another traffic accident.
The emotional impact of the case is great, but in fact there is no need for criminal investigation to intervene.
It's just that now it involves chasing down the fleeing driver, which is a bit more complicated than ordinary traffic accident cases.
However, with current methods, if a traffic accident results in death and then the vehicle escapes, the vehicle will basically not escape.
It can definitely be found, and the dead person is a criminal policeman, so the traffic police detachment will definitely do their best.
Liu Guodong followed Lu Chuan's voice and walked over: "What problem did you find?"
Lao Liu also felt very heavy.
He too will retire one day.
However, who can guarantee that he will survive until then?
"Here, there are tire scorch marks."
Lu Chuan squatted on the ground and scraped the asphalt road with tweezers. His junior tire mark analysis skills allowed him to quickly determine the relevant information left by the scorch marks: "When the vehicle accelerates rapidly, the tires rub against the ground, and the rubber left behind rubs against the ground." trace."
When Liu Guodong heard this, his head was pounding.
"Are you sure it's the tire marks left by the vehicle's acceleration?"
Lu Chuan nodded affirmatively: "The marks left by braking and the marks left by acceleration are because the directions of friction are exactly opposite, so the friction directions of tire marks are also different."
Liu Guodong raised his head and followed the traces on the ground to look at the impact point of Song Kun's car accident.
"You suspect it's not...an accident?"
Going from this direction, the vehicle follows a straight line and reaches exactly the point of impact.
"Ding!"
"Advanced mission: Complete a qualified tire mark analysis and uncover the truth behind the death of detective Song Kun."
Lu Chuan used tweezers to pick up a small part of the scorch mark, put it under his nose and smelled: "It's possible."
"The scorch marks smelled very strong and they didn't stay for more than three hours."
"Moreover," Lu Chuan stood up and pointed to the sandy soil outside the curb: "The sandy soil here has obvious signs of friction."
"This should be a four-wheel drive vehicle. All four tires have grip marks."
“Also, the tires have the same tread pattern and similar levels of wear.”
"The traffic flow on Longjiang Road is not large. The probability of two cars of the same model appearing in a short period of time is not high."
Opening the spot inspection box he carried with him, Lu Chuan dipped a cotton swab into the rubber residue on the scorch marks: "We will go to the impact point later to collect the rubber residue on the tire braking marks and do a comparative analysis of the ingredients."
"By combining it with the tire pattern marks, we can determine whether the vehicle here is the one that hit and killed Song Kun."
Lu Chuan's discovery made Liu Guodong realize the seriousness of the matter.
Traffic accidents and intentional homicide are not the same thing.
Moreover, if Song Kun did not die in a traffic accident, then who would deliberately kill a criminal police officer who was about to retire?
Is it because Song Kun has any cases in his hands now?
Did you find out something terrible?
Or is it the person Song Kun captured before who came out to commit crimes in revenge?
Or is it someone he has any grudge against in his own life?
Each possibility has different consequences.
In other words, it's a world of difference.
Death in a traffic accident is a natural or man-made disaster.
But if he is murdered and the cause is personal, it is an ordinary homicide.
But if it was deliberate revenge, then Song Kun died in the line of duty and was a martyr.
"Xiao Lu, you do the current survey here first, and I'll report to Team Qin."
Lu Chuan nodded with a serious expression.
In fact, Lu Chuan didn't think so much when he first arrived at the scene.
But because there were already traffic police measuring tire mark data near the impact point, he did not step forward.
After all, there are specialties in the art industry.
The traffic police must have more experience in handling traffic accidents than the criminal investigation side.
Therefore, Lu Chuan wandered around the perimeter casually, followed the direction of traffic, and walked a few steps up in the opposite direction.
But I didn't expect to find these details.
A minute later, Qin Yong ran to the corner of the road, and Zhang Yongzhi, the leader of the traffic police detachment, came with him.
"Lu Chuan, are you sure?"
Lu Chuan, who has collected the rubber residue, is now taking photos of the tires.
"Team Qin," Lu Chuan put down the camera and opened the browser window: "This is the pattern of the tire marks here. It should be consistent with the tire pattern left by the brake marks near the impact point."
Although the vehicle's braking mark on the asphalt road is a dark scorch mark, the depth of the scorch mark is slightly different due to the pattern of the tire itself.
In the eyes of professionals, these shades without any trace are actually the tread patterns of tires.
What's more, at the beginning and end of the mark, especially the end of the brake mark, when the vehicle brakes and stops, the rubber residue left by the tire rubber due to high temperature friction will mark the tire mark very clearly.
After receiving Lu Chuan's affirmative answer, Qin Yong's face became extremely ugly.
He murdered the detective and faked the scene of the car accident.
Who is so bold? !
"Are there any other clues?"
Lu Chuan nodded: "I just made a preliminary analysis of the tire marks. Judging from the color of the tire marks, the vehicle involved in the accident should be a passenger car. According to the preliminary measurement, the tire width is 265, so it should be a tire used by a large car or off-road vehicle. "
Seeing Qin Yong frowning, Lu Chuan continued to explain: "Vehicle tires have certain specifications. Passenger cars, engineering vehicles, and trucks have different tire specifications because of their different uses."
"Tires of different specifications have different rubber materials and different colors of scorch marks."
One of the main reasons why tire marks can be used as judicial evidence is that the specifications of tires are fixed.
Typically, tires are differentiated by vehicle type.
And there are fixed English letter logos on the tires.
For example, the English letter PC stands for car tire. Private cars, whether ordinary cars or off-road vehicles, basically use this type of tire.
LT stands for light truck tires, TB stands for truck and bus tires, AG stands for agricultural vehicle tires, OTR stands for engineering vehicle tires, ID stands for industrial vehicle tires, AC stands for aircraft tires, and MC stands for motorcycle tires. .
Lu Chuan pointed to the tire marks on the sand under his feet: "Based on the starting distance between the front and rear tires, the measured wheelbase of the vehicle is 2850. There are grip marks on all four wheels. It should be a four-wheel drive vehicle."
Lu Chuan pointed to Song Kun's body in the distance: "I just heard from the forensic doctor that the direct impact point of Song Kun's body was above the waist and close to the chest."
"Based on this high degree of speculation, the vehicle responsible for the accident should be an off-road vehicle."
"The bumper fragments scattered on the road were white, so it was initially determined that the vehicle involved in the accident was a white four-wheel drive off-road vehicle."
Lu Chuan was completely in the mood: "I don't know much about the model of the vehicle, but there shouldn't be many types of off-road vehicles with a wheelbase of 2850. We can roughly lock in the vehicle brand."
Lu Chuan's thoughts became clearer and clearer, and his attention became more and more concentrated. He did not notice how shocked Qin Yong and Zhang Yongzhi looked now.
